Sunscreen can prevent the most common types of skin cancer -- basal cell and squamous cell carcinomas -- but it does not protect against melanoma, a more rare but deadly type of skin cancer, according to a researcher from Memorial Sloan-Kettering Cancer Center in New York.
Instead, genetic factors such as a tendency to develop moles, combined with fair skin and fair hair increase melanoma susceptibility. Those with red or blond hair and light colored eyes and pale skin were six times more likely to develop melanoma than those with darker features, and those with numerous moles also had six times the melanoma risk as those with fewer moles.
Those who used sunscreen did not have a lower risk of melanoma, even though it has been theorized that preventing sunburns in childhood with sunscreen might lower the risk of cancer.
Based on the evidence, researchers concluded that sunburn itself probably does not cause melanoma, but that it is an important sign of excessive sun exposure, particularly among those who are genetically susceptible because of their skin type.
The study was presented last week at the American Association for the Advancement of Science meeting in Philadelphia. Indeed, because sunscreen prevents sunburn it might encourage light-skinned individuals to spend more time in the sun, possibly increasing melanoma risk, said the researchers.
Cases of melanoma are on the rise, and it is now the 10th most common form of cancer in the US.
Dr. Mercola's Comment:
For the non-physicians who read this, the only skin cancer that we really need to be concerned with is melanoma. All of the other cancers can be caught relatively early and are very rarely fatal.
However, melanoma can be the size of dime and can metastasize to other organs and kill someone relatively quickly. I really do not believe that sunscreen helps many people.
It is a chemical that we have to detoxify and probably the risk to benefit ratio is not justified. There are some researchers who believe that the skin exposure to chlorine that we have through bathing and swimming in chlorinated pools is the main reason we have an increased incidence of melanoma. It is NOT the ozone.
The chlorine exposure in combination with excessive sunshine probably contribute to the increase rate of melanoma that is seen. I also believe that the sun has been given too much negative press.
We NEED sunshine to stay healthy (see above article). If we don't get a regular dose of sunshine we will suffer in many more ways than depression. I am fully convinced that is the reason most of us get sick in the winter as our sunshine exposure is decreased.
One should not have excessive exposure as that is dangerous. However, one should be outside for one hour a day if at all possible. There are 1500 wavelengths of light that will hit your retina and supply you with an essential component of staying healthy.
Sun exposure through your car or home or office window is absolutely not equivalent. There are too many of the valuable wavelengths which are filtered out by the glass.
I am very grateful that we have had such a mild winter this year and we can get our dose of sunshine much sooner this year. Thank you El Nino!